Swimming pool liner

ABSTRACT

An aboveground swimming pool having rigid sidewalls, vertical corners, and a flexible plastic liner. Each corner of the liner has a thermal barrier interjacent the liner and the sidewalls, extending the vertical height of the pool. The thermal barrier retards ice formation in the corners of the pool to prevent damage to the liner.

[ 5] Feb. 29, 1972 United States Patent Kuss ..4/172.12 X ...52/169 ......4/172 ......4/l72 .4/l72.12

3,313,443 4/1967 Dial et 3,429,085 2/ 1969 Stillman, Jr.

3,453,666 7/1969 Hedges...........

3,501,782 3/1970 Schwarz et al..

Primary Examiner-Henry K. Artis Attorney-Owen & Owen ....4/172.12,4/172,4/172.19 ABSTRACT ....E04h 3/16,E04h 3/18 All, 17211, 17221, 17212, An aboveground swimming pool having rigid sidewalls, verti- 4/l72l3 17214 172.19 cal corners, and a flexible plastic liner. Each corner of the liner has a thermal barrier interjacent the liner and the [52] US. [51] Int. Cl. [58] Field of Search [56] References Cited sidewalls, extending the vertical height of the pool. The thermal barrier retards ice formation in the corners of the pool to UNITED STATES PATENTS prevent damage to the liner.

3,072,920 l/l963 Yell0tt..................................4/l72.12 1lClaims,3DrawingFigures II 11 11 111 |ll. ii i! Iii/ Patented Feb. 29, 1972 INVENTOR: RALPH L. Kus s. BY@4A-W v PRIOR ART.

.ATTYS.

SWIMMING POOL LINER BACKGROUND OF THE INVENTION This invention relates to swimming pools, and more particularly to a swimming pool liner having thermal barriers in the corners, interjacent the exterior sidewalls and the liner. The thermal barriers thermally separate the sidewall and liner and retard ice formation in the corners of the pool. Aboveground pools generally have a liner of heavy gauge plastic such as polyvinyl chloride. Initially the aboveground pools were small in size and used primarily by children. However, manufacturers now produce aboveground pools capable of containing a large volume of water. Because of the large volume of water,-

and the difficulty of disassembling the pools, it is common to keep the pool filled with water during the winter months. In cold climates, even partial freezing of the water in the pool causes damage to the pool liner. In particular, the damage often occurs as leaks in the comers of the liner.

A larger area of exterior sidewalls is exposed to the elements at the comer. During cold weather, the greatest heat loss from the sidewalls occurs at the corners. This heat loss causes ice to form at the surface of the water, extending downwardly at the corners of the liner. The rough, often sharp icicles are susceptible to movement by the motion of the water caused by wind, or alternate freezing and thawing. The movement of the icicles punctures the liner at the corners of the pool.

It is the principal object of this invention to provide a liner for an aboveground swimming pool having a thermal barrier interjacent the rigid exterior sidewalls and the liner. During the winter months the thermal barrier retards the formation of ice at the corners of the pool.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view in perspective of an aboveground swimming pool, having rigid sidewalls, a flexible plastic liner having a thermal barrier of the invention, interjacent the sidewalls and the liner,

FIG. 2 is a fragmentary cross-sectional view of a prior art pool not having a thermal barrier, showing ice formation at the comer of the pool; and

FIG. 3 is a fragmentary cross-sectional view, taken along the section line 3-3 of FIG. 1 illustrating the retarding of ice formation by the thermal barrier of the instant invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. I, the preferred embodiment of a swimming pool of this invention includes rigid exterior sidewalls 11, a bottom 12, and a water impervious flexible plastic liner 13. The rigid sidewalls ll frequently are fabricated from sheet metal. The liner 13 can be fabricated from heavy gauge plastic sheet such as polyvinyl chloride.

The rigid sidewalls 11 are provided with lateral supports 14 extending beyond the periphery of the pool 10 to limit the deflection of the sidewalls 1 1 caused by the water contained in the pool 10.

The plastic liner 13 is shown provided with a thermal barrier 15 interjacent the liner l3 and the exterior sidewalls 11, at each vertical comer 16, according to the invention.

FIG. 2 shows a cross-sectional view of a corner of a pool constructed according to the prior art, not having a thermal barrier. A large area of exterior sidewalls 11, at the comers, over a 270 exposure, is exposed to the elements so that, during a cold spell, the initial ice formation takes place at the corners where the heat loss to the atmosphere through the sidewalls is the greatest. This greater heat flow passes through the plastic liner 13, and exterior sidewall 11, lowering the temperature of the water at the comer 16. Ice formation commences at the surface and extends downwardly adjacent the liner 13 at the vertical comers 16 to form a pointed, often sharp, icicle 17. Motion of the water caused by wind, or altermite freezing and thawing, causes the icicle 17 to work up and down to damage the liner 1;! at the corners l6 of the pool 10, in the area denignated by reference number A.

FIG. 3 shows a cross-sectional view taken along the sectional line 3-3 of FIG. 1. A resilient foam thermal barrier 15 is shown interjacent the pool liner 13 and the exterior sidewall 11. The thermal barrier 15 separates the pool liner 13 from the exterior sidewall. Reduction of heat flow from the water in the pool 10, through the pool liner 13 and exterior sidewall 11, retards the formation of the icicle 17 at the comer. Of course, a prolonged cold spell will eventually freeze an ice cap entirely across the pool; however, with the thermal liner in place, the ice formation will proceed across the surface of the pool and around its entire periphery at a more uniform rate, without the initial formation of the damaging icicles at the comers. It has been experimentally determined that ice formation, with the thermal barriers 15 in place, approximates that of a cylindrical pool in that the rate of formation is substantially uniform around the pool periphery, without accelerated formation at the corners.

The thermal barrier is preferably a rigid synthetic insulating foam. Rigid foam is a permanent dispersion of a gas in a rigid plastic, both the gas and the plastic contributing to the insulating properties. The entrapped gas imparts a very low-thermal conductivity (K-factor) to the foam, producing excellent insulating properties. A closed cell structure is desirable since it provides strength at low weight, and also seals the foam against liquid and gas penetration. The high strength provides protection against the deformation caused by the weight of the water in the pool.

In a preferred installation, a pocket or sleeve is formed in the comers of the liner to receive and retain the thermal barrier 15, as indicated at 18 in FIG. 3. However, the thermal barrier can be bonded to the plastic liner in any convenient manner or can be loosely placed inside the outer shell prior to installation of a conventional liner.

As shown in the drawings, the insulating pieces may be a single molded L-shaped piece having a beveled surface on each leg to blend into the inner pool surface. Water pressure against the liner 13 will cause it to smoothly conform to the inner surface of the walls and insulation. In summer use, the insulation is also useful as a resilient padding in the pool corners and will relieve stress on the liner by rounding out or filling the acute comers of the pool structure.

Other advantages of the above-described invention will be apparent and various modifications may be made by those skilled in the art without departing from the spirit and scope of the following claims.

What I claim is:

1. In an aboveground swimming pool construction having rigid exterior sidewalls and a bottom with vertical corners formed by the intersection of adjacent sidewalls with a water impervious flexible plastic liner adjacent said sidewalls and bottom, the improvement comprising a thermal barrier interjacent said liner and said sidewalls at each of said vertical corners, said thennal barn'er extending substantially throughout the height of said sidewalls and laterally along said sidewalls a distance sufficient to thermally separate said exterior sidewalls and said liner in the area of each comer whereby ice formation within said liner at said comers of said pool is retarded.

2. The combination according to claim 1 wherein the thermal barrier is s synthetic foam insulating material.

3. The combination according to claim 1 wherein the thermal barrier is polystyrene foam.

4. The combination according to claim 1 wherein the thermal barrier has a L-shaped cross section having tapered ends adjacent said sidewalls.

5. The combination according to claim 1 wherein the thermal barrier is bonded to said liner.

6. A water impervious flexible plastic liner for an aboveground swimming pool having rigid exterior sidewalls and a bottom with vertical comers formed by the intersection of adjacent sidewalls with said liner, said liner including an insulating barrier positioned adjacent each corner thereof to thermally separate said exterior sidewalls and said liner in the area of each corner whereby ice formation within said liner at said corners of mid pool in retarded.

7. A plastic liner according to claim 6 wherein the thennal barrier is a synthetic foam insulating material.

8. A plastic liner according to claim 6 wherein the thermal barrier is polystyrene foam.

9. A plastic liner according to claim 6 wherein the thermal barrier has a L-shaped cross section having tapered ends adjacent said sidewalls.

10. The combination according to claim 6 wherein the thermal barrier is bonded to said liner.

11. An aboveground swimming pool having rigid metal ex- 

1. In an aboveground swimming pool construction having rigid exterior sidewalls and a bottom with vertical corners formed by the intersection of adjacent sidewalls with a water impervious flexible plastic liner adjacent said sidewalls and bottom, the improvement comprising a thermal barrier interjacent said liner and said sidewalls at each of said vertical corners, said thermal barrier extenDing substantially throughout the height of said sidewalls and laterally along said sidewalls a distance sufficient to thermally separate said exterior sidewalls and said liner in the area of each corner whereby ice formation within said liner at said corners of said pool is retarded.
 2. The combination according to claim 1 wherein the thermal barrier is s synthetic foam insulating material.
 3. The combination according to claim 1 wherein the thermal barrier is polystyrene foam.
 4. The combination according to claim 1 wherein the thermal barrier has a L-shaped cross section having tapered ends adjacent said sidewalls.
 5. The combination according to claim 1 wherein the thermal barrier is bonded to said liner.
 6. A water impervious flexible plastic liner for an aboveground swimming pool having rigid exterior sidewalls and a bottom with vertical corners formed by the intersection of adjacent sidewalls with said liner, said liner including an insulating barrier positioned adjacent each corner thereof to thermally separate said exterior sidewalls and said liner in the area of each corner whereby ice formation within said liner at said corners of said pool is retarded.
 7. A plastic liner according to claim 6 wherein the thermal barrier is a synthetic foam insulating material.
 8. A plastic liner according to claim 6 wherein the thermal barrier is polystyrene foam.
 9. A plastic liner according to claim 6 wherein the thermal barrier has a L-shaped cross section having tapered ends adjacent said sidewalls.
 10. The combination according to claim 6 wherein the thermal barrier is bonded to said liner.
 11. An aboveground swimming pool having rigid metal exterior sidewalls and a bottom with vertical corners formed by the intersection of adjacent sidewalls with a water impervious flexible plastic liner adjacent said sidewalls and liner, said liner having a thermal barrier of synthetic foam insulation, said thermal barrier extending substantially throughout the vertical height of said sidewalls and laterally along said sidewalls a distance sufficient to thermally separate said exterior sidewalls and said liner in the area of each corner whereby ice formation within said liner at said corners of said pool is retarded. 